IPA: /ˈhɔːrmʌŋɡər/
KK: /ˈhɔrˌmʌŋɡər/
A person who engages in or promotes sexual activities for money, often in a derogatory sense.
The novel depicted a whoremonger who exploited vulnerable individuals for profit.
Whoremonger is formed from "whore" (from Old English *hwore*, meaning a woman who engages in sexual activity for payment) and "monger" (from Old English *mangere*, meaning a dealer or trader). The word describes someone who deals in or promotes the activities of prostitution.
Think of a 'dealer' ('monger') in 'whores' ('whore') — that's why whoremonger refers to someone who promotes or engages in prostitution.